The biosynthesis of glycosaminoglycans in normal rat liver and in response to experimental hepatic injury.

The synthesis of glycosaminoglycans in slices from normal and acutely injured rat liver was studied. The rates of incorporation of [14C]-glucosamine into specific types of glycosaminoglycans varied markedly; nearly 90% was incorporated into a fraction containing predominantly heparan sulfate and far less if any heparin; about 9.5% was incorporated into chondroitin 4-and 6-sulfate, and only 0.2% of the radioactivity was found in hyaluronic acid. The rate of synthesis of a fraction having several of the characteristics of keratan sulfate comprised only 0.3% of the synthesis of total glycosaminoglycans. No [14C]hexosamine was incorporated into dermatan sulfate. Following acute hepatic injury, the synthesis of glycosaminoglycans was stimulated by 80 to 100%, and the proportions of various types changed. If calculated on the basis of the specific activity of the precursors of glycosaminoglycans, which was found to be strongly reduced in injured liver, the maximum enhancement of total glycosaminoglycan synthesis was 6.6-fold 5 days after onset of liver injury.